WASHINGTON (Reuters) - California and Wisconsin said the U.S. Department of Homeland Security was incorrect when it notified them last week they were among 21 states whose election systems were targeted by Russian hackers during the 2016 election.

California Secretary of State Alex Padilla said on Thursday DHS notified the state that Russian cyber actors “‘scanned’ California’s Internet-facing systems in 2016, including Secretary of State websites.”

California said after asking for more details “it became clear that DHS’ conclusions were wrong. DHS confirmed that Russian scanning activity had actually occurred on the California Department of Technology statewide network, not any Secretary of State website.”

Padilla said that the notification “was not only a year late, it also turned out to be bad information.”

DHS spokesman Scott McConnell said notifications to 21 states were “based on a variety of sources, including scanning detected from malicious IP addresses and intelligence information that cannot be publicly disclosed.”

The government has “provided additional information and clarity to a number of states,” he said.

DHS ”stands by its assessment that Internet-connected networks in 21 states were the target of Russian government cyber actors seeking vulnerabilities and access to U.S. election infrastructure,” he said.

Wisconsin election officials on Wednesday released an email from DHS that said the IP address targeted was at the Wisconsin Department of Workforce Development, not the state’s elections commission.

DHS told states including Ohio, Alabama, Alaska, Colorado, Connecticut, Florida, Minnesota, Texas, Virginia, Pennsylvania, Delaware, Iowa, Maryland and Washington state they were targeted by Russian hackers but said the hackers were not successful. Arizona and Illinois confirmed last year that they were targets.

There is no evidence any votes were changed, DHS said.

Russia has denied election meddling, and President Donald Trump has denied any collusion with Russia.

“There remains no evidence that the Russians altered one vote or changed one registration,” said Judd Choate, president of the U.S. National Association of State Election Directors.

Homeland Security officials have said that in most of the 21 states only preliminary activity was observed from hackers and a small number of networks were compromised.

U.S. intelligence agencies have concluded the Kremlin orchestrated an operation that included hacking and online propaganda intended to help Trump win, Reuters reported in August.

Several congressional committees are investigating and special counsel Robert Mueller is leading a separate probe into the Russia matter, including whether Moscow colluded with the Trump campaign.